Self-filling fountain pens



Jan. 7,- 1964 D, .1. SILVER SELF-FILLING FOUNTAIN PENS Filed April 27,1962 R m mm om. .V T al w MM I M 3 2 8 7,@ 4 w n 2 Il I 'o' an. Wl[Illill TZZLP l... m mm@ 1- I 1 b5 6 Mm m 9 8 @do e United States PatentO 3,116,719 SELF-FHJLING FUUNTAIN PENS Derrick .lohn Silver, Letchworth,England, assigner to Mentmore Manufacturing Co. Limited, Stevenage,Hertfordshire, England, a company of Great Britain Filed Apr. 27, 1962,Ser. No. 190,743 3 Claims. (Cl. 1Z0-50) This invention relates toself-filling fountain pens of the kind (hereinafter referred to as thekind specifled) in which the reservoir space contains a filling of amaterial offering a multiplicity of capillary passages or intersticeswhich will take up a supply of ink when the nib of the pen is dippedinto body of ink, will then retain such supply and will subsequentlyfeed it to the nib during the action of writing, the filling beingcoupled to the nib by an ink-conducting element such as a wick.

Such fountain pens, in which the reservoir space is vented to theatmosphere at or towards the end remote from the nib, are insensitive tovariations in pressure and temperature and are generally satisfactory.However, it has been found necessary in the past to limit the axialdimension of the filling of material in the reservoir space so as toensure that the quantity of ink initially taken up by the materialduring a filling operation will be stably retained while the pen isvertically disposed. This is due to the fact that the axial dimension orlength of the filling may be made somewhat greater than what is termedherein the stable-column length and yet take up a full charge of inkalthough the excess quantity of ink (representing that portion of thecharge which is absorbed into the part of the filling extending beyondthe end of the stable-column length) tends to be discharged very easilyfrom the filling material, under the action of gravity, when the pen isheld in a vertical position. This discharge, which may occur while thepen is in a pocket of the users clothing, increases the risk of leakageof ink through the air vent of the pen with disadvantageousconsequences. Another drawback of pens having a filling of greater thanstable-column length is the fact that after a small quantity of the inkhas been expended in writing operations, the remaining body of ink inthe filling material tends to move to the end of' the filling remotefrom the nib as soon as the pen is placed nib-uppermost (which is thenormal disposition of the pen while being carried on the person) with aconsequent draining of ink from the portion of the filling adjacent tothe nib. When the pen is again used for writing purposes there issometimes considerable difiiculty in starting the flow of ink to thepoint of the nib and this fault becomes progressively more pronounced asthe quantity of ink held in the filling is reduced.

On the other hand, if the filling of material in the reservoir space ofthe pen is restricted to the stable-column length, it is necessary toemploy an accurately manufactured nib having a slit of very small width.Not only is the nib difficult and costly to make but its writingcharacteristics are somewhat undesirable in that a free flow of ink tothe writing point is unobtainable and the nib is relatively inflexiblewith a hard" feel in use. In addition, a person who writes with a heavypressure can soon put the nib out of set by spreading the points of thenib, with permanent deformation of the metal, until the pen ceases tofunction.

The present invention is concerned with improvements in pens of the kindspecified which shall make it possible to store a larger supply of inkthan usual in the filling material, without risk of leakage of inkduring normal use, so that the nib need not be made to such closetolerances and will write without inconvenient delay after the pen hasbeen kept in the nib-uppermost position for some time.

According to the invention a pen of the kind specified ICC has thefilling of material in the reservoir space of the pen provided as twoseparate bodies, one of which is located adjacent to the nib of the penin permanent ink-feeding relationship to the nib and the other of whichis mounted so that it may move longitudinally under the action of theforce due to gravity towards and away from a position in which it is inink-feeding relationship to the first body, the length of each bodybeing less than the stablecolumn length but the sum of the lengths ofthe bodies being greater than the stable-column length.

One construction of a fountain pen embodying the invention is describedin greater detail below with reference to the accompanying drawings,wherein:

FIG. 1 is a part sectional elevation of the pen in the nib-uppermostposition,

FIG. 2 is a longitudinal section of the pen in the nibdownwardsposition,

FIG. 3 is an end view of the pen taken rom the nibend,

FIG. 4 is a plan View of the feed element of the pen and FIG. 5 is anunder-plan view of this element.

This pen comprises a barrel 1 and a nibssec-tiion Z secured together ata screw-threaded joint 3 (FIG. 2), the end 1a of the barrel remote Afromthe joint being closed and the free end of the nib-section remote fromthe joint being fitted with a nib 4 and a feed element 5. The free endof the nib-section is closed except for an axially extending passage 6(FIGS. 2 and 3) into which is tightly fitted the feed element 5 havingthe nib `Il placed in contact with its upper face and interlockedtherewith by inter-engaging projections and recesses (the projections onthe feed element being shown at 5a in FIG. 4 and one of the recesses ornotches in the edges of the nib being shown at 4a in FIG. 2). The upperface of the feed element has a shallow recess 5b (FIG. 4) formed thereinto contain a piece 7 of the capillary mesh fabric which is to beemployed to constitute the filling of the reservoir space of the pen(las hereinafter (described), this recess extending from near the innerend of the element to near the outer or free end thereof beneath part ofthe length of the slit 4b (FIGS. 2 and 3) in the nib. The underside ofthe element '5 is formed with a longitudinally extending groove 5c(FIGS. 2, 3 and 5) thnough which ink can gain access to the space withinthe nib-section 2, when this is dipped into a body of the ink, -and alsohas abutments 5d adapted to engage a shoulder 6a (FIGS. 2 and 3) formedin the passage `6 in the end of the nibsection in order to limit theextent to iwhich the nib and feed element assembly may be pressed intothe passage. At the appropriate llocation the wall of this passage 6 isformed with spaced longitudinally extending ribs 6b (FIGS. 2 and 3)adapted to bear on the back of the nib 4 and leave between .them achannel in which is disposed the end of ia wick `S that extends (seeFIG. 2) from the free end of the nib-section 2 in close Contact with theback of the nib (over a peut of .the slit 4b therein) to be foldedlacross the inner end of the nib and then folded again to extend alongthe inner surface of the nib section to the other end thereof.

The space within the nib-section is filled with Ia spirally rolledIlength 9 of `a capillary mesh fabric, which roll extends from the innerend of the nib 4 to a short distance beyond the open end 'of thenib-section. A suitable fabric is one knitted from nylon yarn andgenerally known as a tricot The axial length of the fabric roll 9 issomewhat shorter than the stable-column length referred to above.

Within the barrel 1 o-f the pen is a longitudinally extending space 10of circular cross-section that is substantially cylindrical `throughoutits length and is vented to the exterior of the barrel by way of a smallaperture 11 in the wall thereof `at about its centre of length. Freelyslidable within the space in the barrel is a sleeve 12, of a sui-tableplastics composition, for example, in which is contained `a secondspirally rolled length 13 of the capillary mesh fabric, this rollprojecting from the sleeve at each end. The sleeve, which substantiallyfills the crosssection of the space, is weighted, for example, byslipping a tightly-fitting metal sleeve 14 over a reduced diameter endthereof. The length of the second fabric roll 13 is again somewhat lessthan the stable-column length and may be about equal to half the lengthof the space within the barrel. So that the sleeve 12 containing thisroll may slide freely within the barrel `despite the presence of ink inthe latter, either the surfaces of the interior of the barrel and theexterior of the sleeve are treated with a waterarepellent composition orthe sleeve is formed (as shown in FIGS. 1 and 2) with smallprotuberances 12a which will space the exterior of the sleeve from theinterior of the barrel by a short distance.

The combined lengths of the two fabric rolls 9' and 13 give an overalllength which is substantially greater than the stable-column length, forexample, equal to the stablecolurnn length plus 30% to 50%. The meshsize of the fabric employed has, of course, to be taken into account inarriving at the appropriate stable-column length.

A cap is provided in the usual Way (it is not illustrated) to protectthe nib-end of the pen when the latter is out of use.

A pen as described functions in the `following manner.

When the pen is placed vertically with the nib 4 downwards as shown inFIG. 2r, the sleeve carrying t-he second fabric roll 13 slides `downinside the barrel until the lower end `of the roll comes to bear uponthe upper end `of the fabric roll 9 in the nib-section of the pen. Thetwo fabric rolls then constitute a continuous reservoir of a capillarynature into which ink can be inducted or absorbed when the nib end ofthe pen is immersed to a suitable depth in `a body of ink. The inkrises, by capillary action, to the `full height of the composite columncomposed of the two fabric rolls 9 and 13.

On removing the pen from the body of ink and allowing it to drain for ashort time, any ink not held in capillary interstices is relinquishedbut there remains a column of ink of a length exceeding thestable-column length by some 30% to 50% (dependent upon the lengthsselected for the rolls 9 and 13). This ink is not held so stably as itwould be in a column of the stable-column length Iand thus will providean 'adequate flow to the nib 4 without its being necessary to constructthe latter to the high degree of accuracy normally required in acapillary pen.

On inverting the pen to the position shown in FIG. 1, as when placing it(provided with a cap on the nib-end) in a pocket of the users clothing,the sleeve 12 carrying the second fabric roll 13 slides t0 `the closedend of the barrel. In this condition, the reservoir consists of twosections 9 and 13 each of less than the stable-column `length which areseparated by an intervening gap. Consequently, the volume of ink held ineach section is stably retained and there is no risk of undesired`discharge of ink from either section.

Should there happen to be some excess ink in the nibsection 2 of thepen, i.e. ink not held in capillary interstices of the lling 9, thisexcess will ow into the second fabric roll 13 during the inversion ofthe pen and be carried by this roll to the bottom of the barrel. Whenthe pen is again returned to the nib-downwards position, ink carried inthe second fabric roll 13 can again be transferred from the latter tothe fabric roll 9 in the nib-section by reason of the contact betweenthe two fabric rolls.

lt' some ink should be dislodged from the fabric rolls 9 and 13 into thebarrel of the pen, due to the subjection of the pen to shocks, as Vbyits being dropped, this ink is quickly absorbed by the second fabricroll 13 as it reaches the bottom of the barrel.

I claim:

l. A pen of the kind specified having a barrel dening a reservoir space,and a lling of capillary material in the reservoir space of the penprovided as two separate bodies, one of which is tixedly locatedadjacent to the nib of the pen in permanent ink-feeding relationship tothe nib and the other of which is mounted so that it may movelongitudinally under the action of the force due to gravity towards andaway from a position in which it is in ink-feeding relationship to thefirst body, the length of each body being less than the stable-columnlength but the sum of the lengths of the bodies being greater than thestable-column length.

2. A pen according to claim 1, wherein each body of reservoir-fillingcapillary material is a spirally rolled length of fabric.

3. A pen according to claim 2, wherein the movable body of capillarymaterial is held in but projects at each end beyond a sleeve slidablewithin the barrel of the pen.

References Cited in the file of this patent UNITED STATES PATENTS

1. A PEN OF THE KIND SPECIFIED HAVING A BARREL DEFINING A RESERVOIRSPACE, AND A FILLING OF CAPILLARY MATERIAL IN THE RESERVOIR SPACE OF THEPEN PROVIDED AS TWO SEPARATE BODIES, ONE OF WHICH IS FIXEDLY LOCATEDADJACENT TO THE NIB OF THE PEN IN PERMANENT INK-FEEDING RELATIONSHIP TOTHE NIB AND THE OTHER OF WHICH IS MOUNTED SO THAT IT MAY MOVELONGITUDINALLY UNDER THE ACTION OF THE FORCE DUE TO